Samples of raw water and water treated by coagulation with FeSO4 and sedimentation were taken out from a com. water treatment plant and analyzed for pH, total alky.,color, turbidity, total and dissolved org. C, UV254 absorbance, ammonium, nitrite and nitrate N as well as phosphate ions. The treatment resulted in a decrease in C content and UV254 absorbance and in reduction of phosphate ions and ammonia N. No biolog. stability of the water was achieved by the treatment The treated water showed an increased corrosion activity.